Released: June 20, 2001

Stressed-Looking Garden Plants May Be Adjusting for Summer

MANHATTAN, Kan. – Spring keeps changing its mind this year and inserting cool, damp days between periods of summer-like weather.

But any string of 90-degree Fahrenheit days, followed by relatively hot nights, can signal plants to start preparing for extended hot weather. As a result, shallow-rooted new plants and transplants may look a little worrisome for awhile, said Kansas State University horticulturist Chuck Marr.

The plants’ adjustment includes steps gardeners can see, plus ones that go unnoticed:

* Late afternoon wilting becomes common on hot days.

* Top growth slows down.

* Roots extend deeper into the ground.

* To prevent excess water loss, leaves thicken and develop a waxy coating.

"In normal years, the entire transition only takes a week or so. During up-and–down temperatures, it may last a little longer, but plants will soon resume their normal growth cycles," said Marr, who is K-State Research and Extension’s vegetable crops specialist.

Adequate water can be critical to how well plants’ make the transition and go on to produce through summer, he said. For most garden and landscape plants, that means getting about 1 inch of moisture per week, whether through rainfall or irrigation.

"Often, Plains states get that amount of rain through spring. If so, feeling sorry for wilted-looking plants and using irrigation to overwater could hinder, not help, the plants’ adjustment," Marr warned. "Overwatering fosters diseases such as root rot. It also encourages plants to be lazy and keep most of their root system near the surface, where it can dry out quickly throughout the summer."

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K-State Research and Extension is a short name for the Kansas State University Agricultural Experiment Station and Cooperative Extension Service, a program designed to generate and distribute useful knowledge for the well-being of Kansans. Supported by county, state, federal and private funds, the program has county Extension offices, experiment fields, area Extension offices and regional research centers statewide. Its headquarters is on the K-State campus, Manhattan.

Story by:
Kathleen Ward, Communications Specialist
kward@oznet.ksu.edu
K-State Research& Extension News